Microchip-type optical measuring apparatus and optical position adjusting method thereof

ABSTRACT

To provide a microchip-type optical measuring apparatus which is able to automatically perform position adjustment of a microchip with respect to an optical axis of laser with high accuracy. 
     A microchip-type optical measuring apparatus includes an irradiation detection unit which detects light generated by irradiating a microchip with laser, a position adjustment unit which changes a relative position of the microchip with respect to the irradiation detection unit, and a control unit which outputs a movement signal for a position in which an integrated value or an average value of a detected intensity of the light in a preset region becomes high to the position adjustment unit.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of and claims the benefit under 35 U.S.C. § 120 of U.S. patent application Ser. No. 15/875,846, titled “MICROCHIP-TYPE OPTICAL MEASURING APPARATUS AND OPTICAL POSITION ADJUSTING METHOD THEREOF,” filed on Jan. 19, 2018, which is a continuation of and claims the benefit under 35 U.S.C. § 120 of U.S. patent application Ser. No. 14/386,499, titled “MICROCHIP-TYPE OPTICAL MEASURING APPARATUS AND OPTICAL POSITION ADJUSTING METHOD THEREOF,” filed on Sep. 19, 2014, now U.S. Pat. No. 9,915,935, which is a U.S. National Stage Entry under 35 U.S.C. § 371 of International Application No. PCT/JP2013/051800, filed in the Japanese Patent Office as a Receiving Office on Jan. 28, 2013, which claims priority to Japanese Patent Application Number JP2012-080472, filed in the Japanese Patent Office on Mar. 30, 2012, each of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present technology relates to a microchip-type optical measuring apparatus and an optical position adjusting method thereof. More specifically, the present technology relates to a microchip-type optical measuring apparatus or the like which allows an optical position of a microchip to be automatically optimized and to be measured with high accuracy.

BACKGROUND ART

A microparticle measuring apparatus (for example, a flow cytometer) which optically measures characteristics of a microparticle such as a cell is known.

In the flow cytometer, sample liquid including the cell flows through a flow passage formed in a flow cell or a microchip, and a detector detects fluorescence or scattering light generated from the cell by irradiating the cell which through-flows inside the flow passage with laser, so that an optical characteristic of the cell is measured. In addition, in the flow cytometer, as a measurement result of the optical characteristic, a population (a group) which is determined to satisfy a predetermined condition is separately collected from the cell.

For example, in PTL 1, as a microchip-type flow cytometer, “a microparticle splitting device including a microchip provided with a flow passage through which liquid including a microparticle flows, and an orifice which ejects the liquid flowing through the flow passage into a space outside the chip, an oscillating element for discharging the liquid to be liquid droplets in the orifice, a charging unit for applying an electric charge to the discharged liquid droplets, an optical detection unit which detects optical characteristic of the microparticle flowing through the flow passage, counter electrodes which are disposed to face each other and to interpose the liquid droplets moved along a movement direction of the liquid droplets which are discharged into the space outside the chip, and two or more containers which collect the liquid droplets passed between the counter electrodes” is disclosed.

CITATION LIST Patent Literature

PTL 1: Japanese Unexamined Patent Application Publication No. 2010-190680

SUMMARY OF INVENTION Technical Problem

The microparticle measuring apparatus is required to perform position adjustment of a through-flow position of the microparticle inside the flow passage formed in the flow cell or the microchip and an optical axis of the laser with high accuracy, in order to accurately measure the optical characteristic of the microparticle. In the related art, since the position adjustment is manually performed by a user with particles for calibration (calibration beads), the position adjustment requires proficiency, and thus has a problem in reliability or stability. Particularly, in the microchip-type microparticle measuring apparatus, the optical position adjustment is required whenever the microchip is exchanged or is analyzed, and thus the position adjustment is considerably cumbersome and complicated.

Therefore, an object of the present invention is to provide a microchip-type optical measuring apparatus which is able to automatically perform position adjustment of a microchip with respect to an optical axis of laser with high accuracy.

Solution to Problem

In order to solve the problem described above, the present invention provides a microchip-type optical measuring apparatus including an irradiation detection unit which detects light generated by irradiating a microchip with laser, a position adjustment unit which changes a relative position of the microchip with respect to the irradiation detection unit, and a control unit which outputs a movement signal for a position in which an integrated value or an average value of a detected intensity of the light in a preset region becomes high to the position adjustment unit.

In this microchip-type optical measuring apparatus, the control unit may assume that a relationship between a detected position and the integrated value or the average value of the detected intensity of the light follows pre-stored probability distribution, may estimate a distribution parameter of the probability distribution on the basis of a stochastic method, and thus may create the movement signal for the position in which the integrated value or the average value of the detected intensity of the light becomes maximum according to the estimation. The control unit may select the probability distribution according to an irradiation profile of the laser.

In addition, the control unit may output the movement signal for a position in which a variation coefficient of the integrated value or the average value of the detected intensity of the light in a plurality of preset points becomes minimum to the position adjustment unit.

In addition, the control unit may output the movement signal for an area in which an area average of the integrated value of the detected intensity in a plurality of preset areas becomes maximum to the position adjustment unit.

In addition, the control unit may output the movement signal for a position in which the integrated value of the detected intensity in the plurality of preset points becomes maximum to the position adjustment unit.

In addition, the control unit may output the movement signal for a first optimal position in which the integrated value of the detected intensity in the area of a maximum area average becomes maximum, or for a second optimal position in which the variation coefficient in the area of the maximum area average becomes minimum to the position adjustment unit.

In addition, the control unit may output the movement signal for the second optimal position to the position adjustment unit when the first optimal position and the second optimal position are different from each other.

This microchip-type optical measuring apparatus may be configured as a microchip-type microparticle measuring apparatus.

In addition, the present invention provides an optical position adjusting method including a procedure for detecting light which is generated from a microchip by laser irradiation, from a plurality of positions on the microchip, and a procedure for specifying a position in which an integrated value or an average value of a detected intensity of the light in a preset region becomes maximum.

In the procedure for specifying the position, a relationship between a detected position and the integrated value or the average value of the detected intensity of the light may be assumed to follow a pre-stored probability distribution, a distribution parameter of the probability distribution may be estimated on the basis of a stochastic method, and thus the position in which the integrated value or the average value of the detected intensity of the light becomes maximum may be specified by the estimation.

In addition, this optical position adjusting method may further include a procedure for assuming that the integrated value or the average value of the detected intensity of the light from the position in which the integrated value or the average value of the detected intensity of the light is estimated to be maximum by the probability distribution to a predetermined position is in a one-dimensional distribution, and thus for specifying a position in which the integrated value or the average value of the detected intensity of the light becomes maximum by the one-dimensional distribution.

In addition, in the procedure for specifying the position, the position may be set to a position in which a variation coefficient of the integrated value or the average value of the detected intensity of the light in a plurality of preset points becomes minimum.

In addition, this optical position adjusting method may further include a procedure for specifying a position in which an area average of the integrated value of the detected intensity of the light in a plurality of preset areas becomes maximum.

In addition, this optical position adjusting method may further include a procedure for specifying a first optimal position in which the integrated value of the detected intensity in the area of a maximum area average becomes maximum.

In addition, the procedure for specifying the position in which the variation coefficient becomes minimum may be a procedure for specifying a second optimal position in which the variation coefficient in the area of the maximum area average becomes minimum.

In addition, this optical position adjusting method may include a procedure for setting a relative position of the microchip with respect to the laser to the first optimal position or the second optimal position.

Further, the present invention provides an optical position adjusting method of a microchip-type optical measuring apparatus, including a procedure for detecting light which is generated from a microchip by laser irradiation, from a plurality of positions on the microchip, a procedure for specifying a position in which an area average of an integrated value of a detected intensity of the light becomes high, a procedure for specifying a first optimal position in which the integrated value or an average value of the detected intensity in an area where the area average becomes higher, becomes higher, a procedure for specifying a second optimal position in which a variation coefficient of the integrated value or the average value of the detected intensity in the area where the area average becomes higher, becomes smaller, and a procedure for setting a relative position of the microchip with respect to the laser to the first optimal position or the second optimal position.

In the present technology, a cell or a microbe, a biologically-relevant microparticle such as a liposome, or a latex particle or a gel particle, a synthetic particle such as an industrial particle, and the like are broadly included in the “microparticle”.

In the biologically-relevant microparticle, a chromosome, a liposome, a mitochondria, an organelle (a cell organelle), and the like which configure various cells are included. In the cell, an animal cell (a blood cell or the like) and a plant cell are included. In the microbe, a bacteria such as a bacteria coliform, a virus such as a tobacco mosaic virus, a fungus such as a Yeast fungus, and the like are included. Further, in the biologically-relevant microparticle, a biologically-relevant polymer such as a nucleic acid or a protein, or a complex thereof is also able to be included. In addition, the industrial particle may be, for example, an organic or inorganic polymeric material, a metal, and the like. In the organic polymeric material, polystyrene, styrene ⋅ divinylbenzene, polymethylmethacrylate, and the like are included. In the inorganic polymeric material, glass, silica, a magnetic body material, and the like are included. In the metal, a gold colloid, aluminum, and the like are included. Generally, it is ordinary that the shape of the microparticle is spherical, but the shape may also be non-spherical, and the size, mass, or the like is not particularly limited.

Advantageous Effects of Invention

According to the present invention, a microchip-type optical measuring apparatus which is able to automatically perform position adjustment of a microchip with respect to an optical axis of laser with high accuracy is provided.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram for describing a configuration of a microchip-type optical measuring apparatus 1 (a flow cytometer 1) according to the present invention which is configured as a microchip-type flow cytometer.

FIG. 2 is a diagram for describing a configuration of an example of a microchip 2 which is mountable on the flow cytometer 1.

FIG. 3 is a diagram for describing a configuration of an orifice 21 of the microchip 2.

FIG. 4 is a flowchart for describing a control step according to a first embodiment in order to optimize an optical position of the flow cytometer 1.

FIG. 5 is a diagram for describing control of an original point ⋅ reference point movement step S₁ to an area average value maximum position determination step S₃ according to the first embodiment.

FIG. 6 is a diagram for describing control of an area average maximum position movement step S₄ to an integrated value maximum position determination step S₆ according to the first embodiment.

FIG. 7 is a diagram for describing control of a variation coefficient determination step S₇ according to the first embodiment.

FIG. 8 is a flowchart for describing a control step according to a second embodiment in order to optimize the optical position of the flow cytometer 1.

FIG. 9 is a diagram for describing control of a coarse adjustment step S₂₁ according to the second embodiment.

FIG. 10 is a diagram for describing a fixed distribution assumed in the coarse adjustment step S₂₁ according to the second embodiment.

FIG. 11 is a diagram for describing control of a first fine adjustment step S₂₂ according to the second embodiment.

FIG. 12 is a diagram for describing control of a second fine adjustment step S₂₃ according to the second embodiment.

FIG. 13 is a diagram for describing control of a finer adjustment step S₂₄ according to the second embodiment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, best modes for carrying out the present invention will be described with reference to the drawings. Furthermore, embodiments described below indicate an example of a representative embodiment of the present invention, and it is not construed as narrowing the range of the present invention by the embodiments. The description will be provided according to the following order.

1. Microchip-type Optical Measuring Apparatus

(1) Irradiation Detection Unit

(2) Position Adjustment Unit

(3) Oscillating Element

(4) Charging Unit

(5) Deflection Plate

(6) Collection Container

(7) Control Unit or the like

(8) Microchip

2. Optimization Control of Optical Position of Microchip-Type Optical Measuring Apparatus According to First Embodiment of the Present Invention

(1) Original Point ⋅ Reference Point Movement Step S₁

(2) Signal Acquisition Step S₂

(3) Area Average Value Maximum Position Determination Step S₃

(4) Area Average Maximum Position Movement Step S₄

(5) Signal Acquisition Step S₅

(6) Integrated Value Maximum Position Determination Step S₆

(7) Variation Coefficient Determination Step S₇

(8) Position Optimization Step S₈

3. Optimization Control of Optical Position of Microchip-Type Optical Measuring Apparatus According to Second Embodiment of the Present Invention

(1) Coarse Adjustment Step S₂₁

(1-1) Grid-like Signal Acquisition Step S₂₁₁

(1-2) Two-dimensional Distribution Parameter Estimation Step S₂₁₂

(1-3) Maximum Position Movement Step S₂₁₃

(2) First Fine Adjustment Step S₂₂

(2-1) Linear Signal Acquisition Step S₂₂₁

(2-2) One-dimensional Distribution Parameter Estimation Step S₂₂₂

(2-3) Maximum Position Movement Step S₂₂₃

(3) Second Fine Adjustment Step S₂₃

(3-1) Linear Signal Acquisition Step S₂₃₁

(3-2) One-dimensional Distribution Parameter Estimation Step S₂₃₂

(3-3) Maximum Position Movement Step S₂₃₃

(4) Finer Adjustment Step S₂₄

1. Microchip-Type Optical Measuring Apparatus

FIG. 1 is a schematic diagram for describing a configuration of a microchip-type optical measuring apparatus 1 (hereinafter, referred to as a “flow cytometer 1”) according to the present technology which is configured as a microchip-type flow cytometer. In addition, FIG. 2 and FIG. 3 illustrate an example of a microchip 2 which is mountable on the flow cytometer 1. FIG. 2A illustrates a schematic upper surface view, and FIG. 2B illustrates a schematic sectional view corresponding to a cross-section cut along line P-P of FIG. 2A. In addition, FIG. 3 is a diagram for schematically describing a configuration of an orifice 21 of the microchip 2, and FIG. 3A illustrates an upper surface view, FIG. 3B illustrates a sectional view, and FIG. 3C illustrates a front view. FIG. 3B corresponds to the cross-section cut along line P-P of FIG. 2A.

(1) Irradiation Detection Unit

The flow cytometer 1 is provided with an irradiation detection unit which includes a light source 61 for irradiating the microchip 2 with laser L₁, and a detector 62 for detecting light to be detected which is generated by irradiation of the laser L₁. An irradiation direction of the laser L₁ with respect to the microchip 2 (an optical axis of the laser L₁) is illustrated as a Z-axis forward direction of FIG. 1. The light source 61 may be an LD, an LED, or the like.

The laser L₁ is applied into a cell which flows through a sample flow passage 22 of the microchip 2. The detector 62 detects scattering light of the laser L₁ caused by the cell, and fluorescence generated by exciting the cell or fluorescent pigment marked on the cell with the laser L₁. In FIG. 1, the fluorescence generated from the cell which flows through the sample flow passage 22 is indicated by a reference mark F₁.

The irradiation detection unit includes an irradiation system provided with a condensing lens for condensing light by guiding the laser L₁ emitted from the light source 61 to the cell, a dichroic mirror, a band pass filter, or the like. In addition, the irradiation detection unit is configured by a detection system for guiding the light to be detected which is generated from the cell by the irradiation of the laser L₁ to the detector 62 by condensing the light. The detection system is configured by, for example, a photo multiplier tube (PMT), an area imaging element such as a CCD or a CMOS element, or the like.

The light to be detected which is detected by the detection system of the irradiation detection unit is the light which is generated from the cell by the irradiation of the laser L₁, and may be, for example, forward scattering light or lateral scattering light, scattering light such as Rayleigh scattering or Mie scattering, fluorescence, or the like. The fluorescence may be generated from the cell or the fluorescent pigment marked on the cell. The light to be detected is converted to an electric signal, and is used for optical characteristic determination of the cell and automatic adjustment of an optical position (described later).

(2) Position Adjustment Unit

The flow cytometer 1 includes a position adjustment unit 9 which changes a relative position of the microchip 2 with respect to the irradiation detection unit. The position adjustment unit 9 moves the position of the microchip 2 and/or the position of the irradiation detection unit on a plane (an XY plane) perpendicular to the optical axis of the laser L₁. Accordingly, the position adjustment unit 9 adjusts the position of the microchip 2 with respect to the optical axis of the laser L₁, and optimizes the laser L₁ to be applied to a through-flow position of the cell inside the sample flow passage 22.

The position adjustment unit 9 may move at least one of the position of the microchip 2 and the position of the irradiation detection unit including the light source 61 and the detector 62 to an X-axial direction and a Y-axial direction. The position adjustment unit 9 is configured by, for example, a stepping motor or the like. Furthermore, the position adjustment unit 9 may move the relative position of the microchip 2 with respect to the irradiation detection unit to a Z-axial direction (a focus direction of the laser L₁).

(3) Oscillating Element

The flow cytometer 1 includes an oscillating element 3 for discharging laminar flow of sample liquid and sheath liquid including the cell which is ejected from the orifice 21 to be liquid droplets by applying oscillation to the orifice 21 formed in the microchip 2. The oscillating element 3 may be, for example, a piezo element. The discharged liquid droplets are injected to a Y-axis forward direction indicated by an arrow in the drawings as fluid stream S. Furthermore, in the flow cytometer 1, the microchip 2 is exchangeably mounted.

In the flow cytometer 1, the oscillating element 3 may be integrated with the microchip 2, and may be disposed on the apparatus side to be contactable with the mounted microchip 2.

(4) Charging Unit

Positive or negative electric charges are applied to the liquid droplets discharged from the orifice 21 by a charging unit 41. The charging of the liquid droplets is performed by an electrode 42 which is electrically connected to the charging unit 41 and inserted into a sample inlet 23 disposed in the microchip 2. Furthermore, the electrode 42 may be inserted into any one portion of the microchip 2 to electrically come in contact with the sample liquid or the sheath liquid flowing through the flow passage.

In the flow cytometer 1, a frequency of a driving voltage of the oscillating element 3, and switching timing of a voltage (a charge voltage) of the charging unit 41 are synchronized, so that any one of plus and minus electric charges is applied to a part of the liquid droplets discharged from the orifice 21. The electric charge may not be applied to a part of the liquid droplets, and thus a part of the liquid droplets may be uncharged.

(5) Deflection Plate

Further, the flow cytometer 1 includes a pair of deflection plates 51 and 52 which are disposed to face each other and to interpose the fluid stream S. The deflection plates 51 and 52 change a travelling direction of each of the liquid droplets in the fluid stream S by an electric force which acts with respect to the electric charges applied to the liquid droplets. The deflection plates 51 and 52 may be an ordinary electrode. In FIG. 1, a facing direction of the polarizing plates 51 and 52 is illustrated by the X-axial direction.

(6) Collection Container

The fluid stream passed between the deflection plates 51 and 52 is received in any one of a collection container 81, a collection container 82, or a collection container 83. For example, when the deflection plate 51 is positively charged and the deflection plate 52 is negatively charged, the liquid droplets which are negatively charged by the charging unit 41 are collected in the collection container 82, and the positively charged liquid droplets are collected in the collection container 83, respectively. In addition, the liquid droplets which are not charged by the charging unit 41 directly drop to be collected in the collection container 81 without receiving an electrical acting force from the deflection plates 51 and 52. In the flow cytometer 1, the travelling direction of the liquid droplets is controlled according to the characteristic of the cell included in each of the liquid droplets, thereby allowing a target cell having a desired characteristic and a non-target cell other than the target cell to be collected in separate collection containers.

The collection containers 81, 82, and 83 may be a general-purpose plastic tube or a glass tube for laboratory use. It is preferable that the collection containers be exchangeably disposed in the flow cytometer 1. In addition, the collection container for receiving the non-target cell among the collection containers may be connected to a drainage route of the collected liquid droplets. Furthermore, in the flow cytometer 1, the number of collection containers to be disposed is not particularly limited. When more than 3 collection containers are disposed, the respective liquid droplets are induced toward any one of the collection containers according to presence or absence of the electrical acting force between the deflection plates 51 and 52, and the magnitude thereof, and collected in the collection container.

(7) Control Unit or the Like

The flow cytometer 1 includes a data analysis unit for determining the optical characteristic of the cell, a tank unit for accumulating the sample liquid and the sheath liquid, a control unit 10 for controlling each configuration, and the like, which are provided in a usual flow cytometer, in addition to the configuration described above.

The control unit 10 is able to be configured by a general-purpose computer provided with a CPU, a memory, hard disk, and the like, and stores an OS, a program for executing a control step (described later), and the like in the hard disk.

The control unit 10 outputs a movement signal for a position in which a variation becomes small, that is, a position in which an integrated value or an average value of a detected intensity of the light generated from the microchip by the irradiation of the laser L₁ becomes higher (preferably, becomes a maximum value) among regions set in advance to the position adjustment unit 9.

(8) Microchip

The microchip 2 is configured by bonding substrate layers 2 a and 2 b in which the sample flow passage 22 is formed. The sample flow passage 22 is able to be formed in the substrate layers 2 a and 2 b according to injection molding of a thermoplastic resin with a mold. As the thermoplastic resin, plastics which are known as microchip material in the related art, such as polycarbonate, polymethylmethacrylate (PMMA) resin, cyclic polyolefin, polyethylene, polystyrene, polypropylene, and polydimethylsiloxane (PDMS) are able to be adopted.

The sample liquid is introduced to the sample inlet 23, merged into the sheath liquid introduced to a sheath inlet 24, and flows through the sample flow passage 22. The flow of the sheath liquid introduced from the sheath inlet 24 is divided into two directions, and then is merged into the sample liquid at a merging portion with the sample liquid introduced from the sample inlet 23, by sandwiching the sample liquid from the two directions. Accordingly, three-dimensional laminar flow in which sample liquid laminar flow is positioned in the center of sheath liquid laminar flow is formed at the merging portion.

A reference numeral “25” indicates a suction flow passage for removing clogging or air bubbles by applying a negative pressure to the inside of the sample flow passage 22 and by temporarily regurgitating the flow when the clogging or the air bubbles is generated in the sample flow passage 22. One end of the suction flow passage 25 is provided with a suction outlet 251 which is connected to a negative pressure source such as a vacuum pump, and the other end is connected to the sample flow passage 22 at a communication port 252.

A laminar flow width of the three-dimensional laminar flow is narrowed at a throttle portions 261 (refer to FIG. 2) and 262 (refer to FIG. 3) which are formed such that the area of a cross section vertical to a flow direction gradually or progressively becomes smaller upstream to downstream in the flow direction. Subsequently, the three-dimensional laminar flow is ejected from the orifice 21 disposed on one end of the flow passage.

The characteristic of the cell is detected between the throttle portion 261 and the throttle portion 262 of the sample flow passage 22. The cell which is arranged in line at the center of the three-dimensional laminar flow and flows through the sample flow passage 22 is irradiated with the laser L₁ by the irradiation detection unit, and thus the fluorescence F₁ and the scattering light which are generated from the cell are detected (refer to FIG. 2).

A connection portion with respect to the orifice 21 of the sample flow passage 22 is configured as a straight portion 27 which is linearly formed. The straight portion 27 functions to directly inject the fluid stream S from the orifice 21 to the Y-axis forward direction.

The three-dimensional laminar flow ejected from the orifice 21 becomes the liquid droplets by the oscillation applied to the orifice 21 according to the oscillating element 31, and is injected as the fluid stream S (refer to FIG. 1). The orifice 21 is open to an end surface direction of the substrate layers 2 a and 2 b, and a cutout portion 211 is formed between an opening position of the orifice and the end surfaces of the substrate layers. The cutout portion 211 is formed by cutting out the substrate layers 2 a and 2 b between the opening position of the orifice 21 and the end surfaces of the substrates such that the diameter L of the cutout portion 221 is larger than the opening diameter 1 of the orifice 21 (refer to FIG. 3C). It is preferable that the diameter L of the cutout portion 211 be equal to or greater than two times larger than the opening diameter 1 of the orifice 21 in order not to disturb the movement of the liquid droplets discharged from the orifice 21.

2. Optimization Control of Optical Position of Microchip-Type Optical Measuring Apparatus According to First Embodiment of the Present Technology

FIG. 4 is a flowchart for describing a control step in order to optimize an optical position of the microchip 2 of the flow cytometer 1. The control step includes a procedure of an “original point ⋅ reference point movement step S₁”, a “signal acquisition step S₂”, an “area average value maximum position determination step S₃”, an “area average maximum position movement step S₄”, a “signal acquisition step S₅”, an “integrated value maximum position determination step S₆”, a “variation coefficient determination step S₇”, and a “position optimization step S₈”. Hereinafter, each procedure will be described.

(1) Original Point ⋅ Reference Point Movement Step S₁

When a starting signal of an analysis is input by a user, the control unit 10 outputs the movement signal to the position adjustment unit 9, and the position adjustment unit 9 moves the relative position of the microchip 2 with respect to the irradiation detection unit to an initial position (refer to an original point O of FIG. 5) set in advance. When the relative position is at the original point O, the laser L₁ emitted from the irradiation detection unit is applied to the original point O on the microchip 2. The relative position is changed by moving at least one of the position of the microchip 2 or the position of the irradiation detection unit including the light source 61 and the detector 62 to the X-axial direction and the Y-axial direction, and, hereinafter, a case where the relative position is changed by moving the position of the microchip 2 will be described as an example.

Next, the control unit 10 starts to allow the sample liquid and the sheath liquid to flow toward the sample inlet 23 and the sheath inlet 24 of the microchip 2 by driving a pump of the tank portion which accumulates the sample liquid and the sheath liquid. It is preferable that the sample liquid include a calibration bead. Further, the control unit 10 starts to apply the oscillation to the orifice 21 by the oscillating element 3. Accordingly, the three-dimensional laminar flow of the sample liquid and the sheath liquid injected from the orifice 21 is discharged to be the liquid droplets, and thus the fluid stream S is generated.

After starting the flow of the sample liquid and the sheath liquid, the control unit 10 outputs the movement signal to the position adjustment unit 9, and the position adjustment unit 9 moves the position of the microchip 2 to a reference point Do from the original point O (refer to an arrow of FIG. 5). When the relative position of the microchip 2 with respect to the irradiation detection unit is at the reference point Do, the laser L₁ emitted from the irradiation detection unit is applied to the reference point Do on the microchip 2.

The reference point Do is set in advance in the vicinity of the position in which the characteristic of the cell of the microchip 2 is able to be detected (that is, an optimal position which is determined by steps described later). More specifically, the reference point Do is the vicinity between the throttle portion 261 and the throttle portion 262 of the sample flow passage 22 (refer to FIG. 3).

(2) Signal Acquisition Step S₂

In this step S₂, the fluorescence or the scattering light (hereinafter, simply referred to as the “fluorescence”) generated from a plurality of positions on the microchip 2 which includes the reference point Do is detected by the irradiation detection unit. In this step S₂, the position on the microchip 2 in which the fluorescence is detected is illustrated by a reference numeral D in FIG. 5. In the drawings, a case where 24 detected positions D including the reference point Do are set, and the fluorescence is detected from the detected positions D in which the number of arrangements M₁ of the X-axial direction is arranged in 8 rows, and the number of arrangements N₁ of the Z-axial direction is arranged in 3 rows is illustrated as an example.

In a region in which the detected positions D are set, the sample flow passage 22 is included, and the number of detected positions D and an arrangement aspect are not particularly limited but arbitrarily set insofar as the sample flow passage 22 is included in the region. It is preferable that the detected positions D be arranged in a reticular pattern in the X-axial direction and the Z-axial direction, as illustrated. In this case, arrangement intervals W and H of the X-axial direction and the Z-axial direction of the detected positions D are able to be properly set according to a flow passage width (a flow passage diameter) of the sample flow passage 22 and the number of arrangements M₁ and N₁ of the detected positions D in the X-axial direction and the Z-axial direction. The flow passage width of the sample flow passage 22 is approximately 70 to 100 μm, and when M₁ is 8 and Ni is 3, the arrangement intervals W and H are set, for example, to 25 and 75 μm, respectively.

The detection of the fluorescence is performed with respect to one detected position D for a predetermined time. The fluorescence detected for the predetermined time is integrated, converted to the electric signal, and output to the control unit 10. The fluorescence is able to be detected by performing scanning of the laser L₁ in the X-axial direction and the Z-axial direction, by sequentially applying the laser to each detected position D, and by detecting the fluorescence to be generated. Alternatively, the fluorescence from each of the detected positions D may be collectively detected by an area imaging element according to the irradiation of the laser L₁.

(3) Area Average Value Maximum Position Determination Step S₃

In this step S₃, the control unit 10 calculates an area average of the integrated value of the detected intensity with respect to each of the detected positions D, and automatically determines the detected position D where the area average becomes higher, preferably, the detected position D where the area average is the maximum value.

The “area average” indicates an average of the integrated value of the detected intensity obtained by one detected position D, and a plurality of detected positions D within a predetermined distance range from the one detected position. In FIG. 5, a case where the area average is an average of the integrated value of the detected intensity obtained by one detected position D₁, and detected positions D₂ to D₉ within the distance range of 2 W in the X-axial direction from the detected position D₁ and 2H in the Z-axial direction from the detected position D₁ is illustrated.

Setting how far the distance range is from the one detected position D as the area average is able to be properly determined according to the flow passage width (the flow passage diameter) of the sample flow passage 22, and the arrangement intervals W and H.

The control unit 10 compares the calculated area average to each of the detected positions D, and determines the detected position D where the area average becomes higher, preferably, the detected position D where the area average is the maximum value. Here, a case where the area average is the maximum value in the detected position D₁ will be described.

Since the fluorescence is strongly generated in the sample flow passage 22 through which the calibration bead or the cell flows, it is possible to consider that the sample flow passage 22 is positioned within a region R₁ where the detected positions D₁ to D₉ in which the area average is the maximum value are formed in conjunction.

(4) Area Average Maximum Position Movement Step S₄

When the detected position D₁ where the area average is the maximum value is specified, the control unit 10 outputs the movement signal to the position adjustment unit 9, and the position adjustment unit 9 moves the position of the microchip 2 to the detected position D₁ from the reference point Do (refer to an arrow of FIG. 6).

(5) Signal Acquisition Step S₅

In this step S₅, the detection of the fluorescence which is generated from a plurality of positions within the region R₁ where the area average is the maximum value is performed by the irradiation detection unit. The detected positions D of the fluorescence in this step S₅ are illustrated in an enlarged view of FIG. 6. In the drawings, a case where the fluorescence is detected from the detected positions D of (M₂×N₂) in which M₂ rows in the X-axial direction and N₂ rows in the Z-axial direction are arranged, including the detected position D₁ where the area average is the maximum value is illustrated as an example.

Arrangement intervals w and h of the detected positions D in the X-axial direction and the Z-axial direction are able to be properly set according to the flow passage width (the flow passage diameter) of the sample flow passage 22 and the number of arrangements M₂ and N₂ in the X-axial direction and the Z-axial direction. The number of arrangements M₂ and N₂ are, for example, 11 and 7, respectively. The row intervals w and h are set, for example, to 5 and 25 μm, respectively. Furthermore, in this step S₅, the number of detected positions D and the arrangement aspect are not particularly limited.

The detection of the fluorescence is performed with respect to the one detected position D for the predetermined time. The fluorescence detected for the predetermined time is converted to the electric signal and output to the control unit 10. The fluorescence is detected by performing scanning of the laser L₁ in the X-axial direction and the Z-axial direction to sequentially scan each detected position D, and by detecting the fluorescence to be generated. Alternatively, the fluorescence from each of the detected positions D may be collectively detected by the irradiation of the laser L₁ according to an area imaging element.

(6) Integrated Value Maximum Position Determination Step S₆

In this step S₆, the control unit 10 calculates either one or both of the integrated value and the average value of the detected intensity with respect to each of the detected positions D, and a variation coefficient (a CV value) thereof. Hereinafter, a process using the integrated value of the detected intensity and the CV value thereof will be described as an example.

The control unit 10 compares the calculated integrated value of the detected intensity with respect to each of the detected positions D, and determines the detected position D where the integrated value becomes higher, preferably, the detected position D (a first optimal position) where the integrated value is the maximum value. Here, a case where the integrated value is the maximum value in the detected position D₁₁ will be described (refer to FIG. 6).

(7) Variation Coefficient Determination Step S₇

Next, the control unit 10 compares the CV values between the detected position D₁₁ where the integrated value is the maximum value and the adjacent detected positions D₁₂ to D₁₉, and automatically determines the presence or absence of the detected position D (a second optimal position) to which a CV value smaller than that of the detected position D₁₁ is applied (refer to FIG. 7).

(8) Position Optimization Step S₈

In step S₇, when the detected position D to which the CV value smaller than that of the detected position D₁₁ where the integrated value is the maximum value is applied is not found in any of the detected position D₁₁ and the adjacent detected positions D₁₂ to D₁₉, the control unit 10 moves the position of the microchip 2 to the detected position D₁₁ from the detected position D₁. At this time, both the detected position (the first optimal position) where the integrated value is the maximum value and the detected position (the second optimal position) where the CV value is the minimum value are coincident with each other in the detected position D₁₁.

In addition, in step S₇, when the detected position D to which the CV value smaller than that of the detected position D₁₁ is applied is found in any one of the detected positions D₁₂ to D₁₉, the control unit 10 moves the position of the microchip 2 to the detected position D (for example, the detected position D₁b) from the detected position D₁. At this time, the detected position (the first optimal position) where the integrated value is the maximum value and the detected position (the second optimal position) where the CV value is the minimum value are not coincident with each other.

The detected position D₁₁ where the integrated value is the maximum value is a position where the fluorescence is most strongly generated, and is able to be considered as a through-flow position of the calibration bead or the cell in the sample flow passage 22. That is, when the relative position of the microchip 2 with respect to the irradiation detection unit is in the detected position D₁₁, the laser L₁ emitted from the irradiation detection unit is applied to the through-flow position of the calibration bead or the like in the sample flow passage 22.

In some cases even though the detected position D₁₁ where the integrated value is the maximum value is not the through-flow position of the calibration bead or the like in the sample flow passage 22, the integrated value of the fluorescence intensity may be the maximum value. For example, when the detected position D₁₁ is coincident with a flow passage wall of the micro-flow passage 22, the fluorescence intensity which is abnormally high due to reflecting, scattering, or the like of the fluorescence may be sporadically detected. In this case, a variation is generated in the fluorescence intensity which is detected in the position, and the CV value of the integrated value of the fluorescence intensity becomes high.

When the detected position D₁₁ is coincident with the flow passage wall of the micro-flow passage 22, or the like, it is possible to consider the detected position D₁₈ to which a smaller CV value is applied among the detected position D₁₁ and the adjacent detected positions as the through-flow position of the calibration bead or the like in the sample flow passage 22. That is, when the relative position of the microchip 2 with respect to the irradiation detection unit is in the detected position D₁₈, the laser L₁ emitted from the irradiation detection unit is applied to the through-flow position of the calibration bead or the like in the sample flow passage 22.

As described above, in the flow cytometer 1, the relative position of the microchip 2 with respect to the laser L₁ is set to the position where the integrated value or the average value of the detected intensity of the fluorescence generated from the microchip 2 by the irradiation of the laser L₁ becomes higher or the position where the CV value becomes smaller. Accordingly, in the flow cytometer 1, the through-flow position of the cell in the sample flow passage 22 of the microchip 2, and the optical axis of the laser L₁ are automatically positioned with high accuracy, and thus it is possible to simply perform high accuracy measurement.

In addition, in the flow cytometer 1, the optical position of the microchip 2 is optimized by a two-staged procedure of a coarse adjustment for specifying the position where the area average of the integrated value of the detected intensity of the fluorescence becomes higher (steps S₂ and S₃), and a fine adjustment for specifying the position where the integrated value or the average value becomes higher within the region where the area average becomes higher or the position where the CV value becomes smaller (steps S₅ to S₇). Accordingly, it is possible to rapidly perform the optimization of the optical position of the microchip 2 with a small processing load.

3. Optimization Control of Optical Position of Microchip-Type Optical Measuring Apparatus According to Second Embodiment of the Present Technology

FIG. 8 is a flowchart for describing a control step according to a second embodiment in order to optimize the optical position of the flow cytometer 1. The control step of this embodiment includes a procedure of an “original point ⋅ reference point movement step S₁”, a “coarse adjustment step S₂₁”, a “first fine adjustment step S₂₂”, a “second fine adjustment step S₂₃”, and a “finer adjustment step S₂₄”. Hereinafter, each procedure will be described. Furthermore, since the original point ⋅ reference point movement step S₁ is a process which is substantially identical to the original point ⋅ reference point movement step S₁ of the first embodiment, except that the reference point D₀ (refer to FIG. 5 again) corresponds to a reference point P₀ illustrated in FIG. 9 (described later), the description thereof will be omitted.

(1) Coarse Adjustment Step S₂₁

FIG. 9 is a diagram for describing control of a coarse adjustment step S₂₁ according to this embodiment.

The coarse adjustment step S₂₁ includes a procedure of a “grid-like signal acquisition step S₂₁₁”, a “two-dimensional distribution parameter estimation step S₂₁₂”, and a “maximum position movement step S₂₁₃”. Hereinafter, each procedure will be described.

(1-1) Grid-Like Signal Acquisition Step S₂₁₁

In this step S₂₁₁, the detection of the fluorescence from a plurality of detected positions D₂₁ set in advance is performed by the irradiation detection unit (refer to FIG. 9A). In this step S₂₁₁, a position on the microchip 2 in which the detection of the fluorescence is performed is illustrated by a reference numeral D₂₁ in FIG. 9A. In FIG. 9A, a case where the fluorescence is detected from the detected positions D₂₁ in which 6 rows in the X-axial direction and 7 rows in the Z-axial direction are arranged, centered on the reference point P₀ is illustrated as an example.

In a region in which the detected positions D₂₁ are set, the sample flow passage 22 is included, and the number of detected positions D₂₁ and the arrangement aspect are not particularly limited but arbitrarily set insofar as the sample flow passage 22 is included in the region. It is preferable that the detected positions D₂₁ be arranged in a reticular pattern in the X-axial direction and the Z-axial direction, as illustrated in FIG. 9A. In this case, arrangement intervals W₂ and H₂ of the detected positions D₂₁ in the X-axial direction and the Z-axial direction are able to be properly set according to the flow passage width (the flow passage diameter) of the sample flow passage 22 and the number of arrangements M₃ and N₃ of the detected positions D₂₁ in the X-axial direction and the Z-axial direction. The arrangement intervals W₂ and H₂ are set, for example, to 62.5 and 125 μm, respectively. The detection of the fluorescence is performed substantially similarly to the signal acquisition step S₂ of the first embodiment.

(1-2) Two-Dimensional Distribution Parameter Estimation Step S₂₁₂

In this step S₂₁₂, the control unit 10 assumes that a relationship between each of the detected positions D₂₁ and the integrated value or the average value of the detected intensity of the fluorescence follows two-dimensional probability distribution. Further, for the detected position and the detected intensity acquired in step S₂₁₁, and an irradiation profile of the laser indicating a relationship between an irradiation position and an irradiation intensity, the detected intensity of each of the detected positions has a correlative relationship with the irradiation intensity of a corresponding irradiation position. For this reason, it is preferable that the assumed probability distribution be selected according to the irradiation profile of the laser.

For example, when the irradiation profile is in the shape of a top-hat beam as illustrated in FIG. 10A (described later), the control unit 10 is able to assume uniform distribution as a probability distribution model.

On the other hand, when the irradiation profile is in the shape of a Gaussian beam as illustrated in FIG. 10B (described later), normal distribution is able to be assumed as the probability distribution model. Thus, it is possible to adjust the optical position according to the optical characteristic of the laser of the apparatus with high speed and high accuracy by selecting the probability distribution according to the irradiation profile of the laser.

In addition, when it is assumed that the relationship between each of the detected positions D₂₁ and the integrated value or the average value of the detected intensity of the fluorescence follows the two-dimensional probability distribution, the control unit 10 estimates a distribution parameter of the probability distribution by a stochastic method, on the basis of stochastic information. For example, the control unit 10 is able to estimate the distribution parameter (an average (a center position of the distribution), dispersion (spread of the distribution), or the like) with respect to each integrated value or average value by a maximum likelihood estimation method.

In this maximum likelihood estimation method, at the time of estimating the relationship between the detected intensity and the detected position to be in the two-dimensional normal distribution, it is possible to estimate where the center position (the position where the detected intensity is maximum) of the two-dimensional normal distribution is at the time of maximizing likelihood, on the basis of the probability distribution model stored in the control unit 10 in advance. According to this maximum likelihood estimation method, it is possible to estimate the position (an optical axis center position of the laser L₁) where the detected intensity is maximum with high accuracy even when data of the detected intensity is small.

(1-3) Maximum Position Movement Step S₂₁₃

In this step S₂₁₃, the control unit 10 outputs the movement signal for a position P₁ where the integrated value or the average value of the detected intensity in the probability distribution estimated in the probability distribution estimation step S₂₁₂ becomes higher, and preferably, becomes the maximum value to the position adjustment unit 9. Accordingly, as illustrated in FIG. 9C, the position adjustment unit 9 moves the position of the microchip 2 to the position P₁ from the reference point P₀.

Here, a calculating method of the maximum position will be described with reference to FIG. 10. FIG. 10 is a diagram illustrating a state where the two-dimensional probability distribution is viewed from one direction. In FIG. 10A, top-hat distribution (uniform distribution) is illustrated. When the probability distribution is estimated to be the top-hat distribution, the control unit 10 determines a center position of an edge E1 and an edge E2 in FIG. 10A as the position where the detected intensity is maximum.

On the other hand, in FIG. 10B, Gaussian distribution is illustrated. When the probability distribution is estimated as the Gaussian distribution, as illustrated in FIG. 10B, it is possible to set a position where the integrated value or the average value of the detected intensity has a maximum value b to a position where an inclination is 0 (an inclination a). In the flow cytometer 1, it is preferable that the optical profile of the laser be the Gaussian distribution, and in this case, the distribution of the integrated value or the average value of a plurality of detected intensities may be the Gaussian distribution.

Thus, in the coarse adjustment step S₂₁, the integrated value or the average value of the detected intensity of the light in a plurality of detected positions D₂₁ is estimated as a specified two-dimensional probability distribution, and it is possible to move the microchip 2 to the position where the integrated value or the average value of the detected intensity of the light in the probability distribution becomes higher, and preferably, becomes the maximum value.

As described above, according to the optical position adjusting method of this embodiment, it is possible to improve position adjustment accuracy of the microchip 2 without increasing the number of detected positions D₂₁, by estimating the probability distribution of the detected intensity of each of the detected positions D₂₁.

(2) First Fine Adjustment Step S₂₂

FIG. 11 is a diagram for describing control of a first fine adjustment step S₂₂ according to this embodiment. The first fine adjustment step S₂₂ includes a procedure of a “linear signal acquisition step S₂₂₁”, a “one-dimensional distribution parameter estimation step S₂₂₂”, and a “maximum position movement step S₂₂₃”. Hereinafter, each procedure will be described.

(2-1) Linear Signal Acquisition Step S₂₂₁

In this step S₂₂₁, centered on the position P₁ which is set in the coarse adjustment step S₂₁, the detection of the fluorescence from a plurality of detected positions d₂₂ which are arranged in the X-axial direction is performed (FIG. 11A). An interval W₂₂ to be detected and the number of arrangements of the detected positions d₂₂ are able to be properly set. In FIG. 11A, a case where 19 detected positions d₂₂ are arranged in the X-axial direction, centered on the position P₁ is illustrated as an example. The detection of the fluorescence is performed substantially similarly to the signal acquisition step S₂ of the first embodiment.

(2-2) One-Dimensional Distribution Parameter Estimation Step S₂₂₂

In this step S₂₂₂, the control unit 10 assumes that a relationship between each of the detected positions d₂₂ and the integrated value or the average value of the detected intensity of the fluorescence follows a one-dimensional distribution stored in a memory or the like. For example, when the data of the detected intensity illustrated in FIG. 11B is obtained, the control unit 10 sets the one-dimensional distribution to an Nth-order polynomial model, and thus it is possible to calculate a maximum value on the basis of a least-square method. Setting the one-dimensional distribution to the Nth-order polynomial model allows a variation of the distribution of the optical profile due to a design variation or the like of each component configuring the flow cytometer 1 to be handled with high accuracy, compared to a case where the one-dimensional distribution is set to the normal distribution.

Here, at the time of setting the distribution to the Nth-order polynomial model, while accuracy increases as the order becomes higher, it is susceptible to an effect due to an error of the detected intensity of each of the detected positions d₂₂ when the order is too high, and thus it is preferable that the order be, for example, fourth-order.

(2-3) Maximum Position Movement Step S₂₂₃

In this step S₂₂₃, the control unit 10 outputs the movement signal for the position P2 where the integrated value or the average value of the detected intensity in the one-dimensional distribution assumed in the one-dimensional parameter estimation step S₂₂₂ becomes higher, and preferably, becomes the maximum value to the position adjustment unit 9. Accordingly, as illustrated in FIG. 11C, the position adjustment unit 9 moves the position of the microchip 2 to the position P2 from the position P₁. Furthermore, a case where the position P2 illustrated in FIG. 11C is on the detected position d₂₂ is illustrated as an example, but the position P2 may be between two detected positions d₂₂.

Thus, in the first fine adjustment step S₂₂, it is possible to adjust the position of the microchip 2 adjusted in the coarse adjustment step S₂₁ with high accuracy. Particularly, the position adjustment of the microchip 2 is performed on the basis of the detected intensity of the detected positions d₂₂ which are arranged in one direction. For this reason, it is possible to reduce the number of data items to be detected, compared to a case where the position adjustment is performed on the basis of the intensity of the detected positions which are arranged in a plurality of directions, for example, in a reticular pattern. Accordingly, even though the number of arrangements increases, and accuracy of the data increases, it is possible to inhibit data detection time from being increased by narrowing the interval of the detected positions d₂₂, compared to a case where the data is two-dimensionally acquired.

(3) Second Fine Adjustment Step S₂₃

FIG. 12 is a diagram for describing control of a second fine adjustment step S₂₃ according to this embodiment. The second fine adjustment step S₂₃ includes a procedure of a “linear signal acquisition step S₂₃₁”, a “one-dimensional parameter estimation step S₂₃₂”, and a “maximum position movement step S₂₃₃”.

As illustrated in FIGS. 12A to 12C, the control of this step S₂₃ is substantially identical to the control of the first fine adjustment step S₂₂ which is described with reference to FIGS. 11A to 11C, except that the microchip 2 is moved to the position P₃ from the position P2 in the Y-axial direction on the basis of the detected intensity of detected positions d₂₃ which are arranged in the Y-axial direction, centered on the position P2, instead of moving the microchip 2 to the position P2 from the position P₁ in the X-axial direction on the basis of the detected intensity of the detected positions d₂₂ which are arranged in the X-axial direction. For this reason, the description thereof will be omitted here.

Here, in the first fine adjustment step S₂₂, the position adjustment is performed in the X-axial direction (a flow width direction of the microchip 2), and in the second fine adjustment step S₂₃, the position adjustment is performed in the Z-axial direction (a focus direction of the laser L₁). Since the Z-axial direction has a wider optical profile width (the detected intensity of the fluorescence is high in a wide range) compared to the X-axial direction, the position adjustment in the Z-axial direction is likely to be performed with high accuracy according to a process performed in the coarse adjustment step S₂₁ described above, compared to the position adjustment in X-axial direction. For this reason, in the coarse adjustment step S₂₁, it is preferable that the Z-axial direction in which the position adjustment is performed with higher accuracy be fixed first, and then the position adjustment of the microchip 2 in the X-axial direction be performed. Accordingly, it is preferable that the first fine adjustment step S₂₁ and the second fine adjustment step S₂₂ be performed in this order.

In the second fine adjustment step S₂₃, the position adjustment of the microchip 2 is performed in a direction different from the direction of the fine adjustment in the first fine adjustment S₂₂, thereby allowing the position adjustment to be performed with higher accuracy.

(4) Finer Adjustment Step S₂₄

FIG. 13 is a diagram for describing control of the second fine adjustment step S₂₃ according to this embodiment. The finer adjustment step S₂₄ includes a procedure of a “signal acquisition step S₂₄₁”, an “integrated value maximum position determination step S₆”, a “variation coefficient determination step S₇”, and a “position optimization step S₈”.

As illustrated in FIG. 13A, first, in the signal acquisition step S₂₄₁, the detection of the fluorescence is performed in a plurality of detected positions d₂₄, centered on the position P₃ which is set in the second fine adjustment step S₂₃. In FIG. 13A, a case where the number of arrangements M₄ of the X-axial direction is 11 rows, and the number of arrangements Ni of the Z-axial direction is 3 rows is illustrated as an example. The detection of the fluorescence is performed substantially similarly to the signal acquisition step S₂ of the first embodiment.

Next, after performing the detection of the fluorescence in the signal acquisition step S₂₄₁, the integrated value maximum position determination step S₆, the variation coefficient determination step S₇, and the position optimization step S₈ are performed substantially similarly to the integrated value maximum position determination step S₆, the variation coefficient determination step S₇, and the position optimization step S₈ of the control step of the first embodiment (refer to FIG. 13B and FIG. 13C).

Thus, the microchip 2 is moved to the most suitable position (moved to P₄ from P₃ in FIG. 13C).

Furthermore, in this embodiment, each process is described in an order of the “coarse adjustment step S₂₁”, the “first fine adjustment step S₂₂”, the “second fine adjustment step S₂₃”, and the “finer adjustment step S₂₄”, but, for example, the “coarse adjustment step S₂₁”, the “first fine adjustment step S₂₂”, and the “second fine adjustment step S₂₃” may be repeated for a plurality of times. In addition, only the “coarse adjustment step S₂₁”, the “first fine adjustment step S₂₂”, and the “second fine adjustment step S₂₃” are performed at once or a plurality of times, and the “finer adjustment step S₂₄” may be omitted.

As described above, according to the optical position adjusting method of this embodiment, the relationship between each of the detected positions and the detected intensity is assumed to follow the specified probability distribution model, and the distribution parameter is estimated on the basis of the stochastic method, thereby allowing the position adjustment of the microchip 2 to be performed with high accuracy in a rapid process, without increasing the number of detected positions.

In the microchip-type optical measuring apparatus according to the present technology, an apparatus for optically measuring an object to be measured which is introduced to a region having the microchip formed therein is broadly included in addition to the microparticle measuring apparatus (the flow cytometer). In addition, the optical position adjusting method according to the present invention is able to be broadly applied to the entire apparatus for optically measuring an object to be measured which is introduced to a region having the microchip formed therein other than the microparticle measuring apparatus (the flow cytometer).

The microchip-type optical measuring apparatus according to the present technology is able to be configured as the following.

(1) A microchip-type optical measuring apparatus, including:

an irradiation detection unit which detects light generated by irradiating a microchip with laser;

a position adjustment unit which changes a relative position of the microchip with respect to the irradiation detection unit; and

a control unit which outputs a movement signal for a position in which an integrated value or an average value of a detected intensity of the light in a preset region becomes high to the position adjustment unit.

(2) The microchip-type optical measuring apparatus according to (1), in which the control unit assumes that a relationship between a detected position of the light and the integrated value or the average value of the detected intensity of the light follows a pre-stored probability distribution, estimates a distribution parameter of the probability distribution on the basis of a pre-stored stochastic method, and thus creates the movement signal for the position in which the integrated value or the average value of the detected intensity of the light becomes maximum by the estimation.

(3) The microchip-type optical measuring apparatus according to (2), in which the control unit assumes the probability distribution according to an irradiation profile of the laser.

(4) The microchip-type optical measuring apparatus according to any one of (1) to (3), in which the control unit outputs the movement signal for a position in which a variation coefficient of the integrated value or the average value of the detected intensity of the light in a plurality of preset points becomes minimum to the position adjustment unit.

(5) The microchip-type optical measuring apparatus according to (4), in which the control unit outputs the movement signal for an area in which an area average of the integrated value of the detected intensity in a plurality of preset areas becomes maximum to the position adjustment unit.

(6) The microchip-type optical measuring apparatus according to (5), in which the control unit outputs the movement signal for a position in which the integrated value of the detected intensity in the plurality of preset points becomes maximum to the position adjustment unit.

(7) The microchip-type optical measuring apparatus according to (6), in which the control unit outputs the movement signal for a first optimal position in which the integrated value of the detected intensity in the area of a maximum area average becomes maximum, or for a second optimal position in which the variation coefficient in the area of the maximum area average becomes minimum to the position adjustment unit.

(8) The microchip-type optical measuring apparatus according to (7), in which the control unit outputs the movement signal for the second optimal position to the position adjustment unit when the first optimal position and the second optimal position are different from each other.

(9) The microchip-type optical measuring apparatus according to (1) to (8), in which the microchip-type optical measuring apparatus is a microchip-type microparticle measuring apparatus.

In addition, the optical position adjusting method of a microchip-type optical measuring apparatus according to the present technology is able to be configured as the following.

(1) An optical position adjusting method, including:

a procedure for detecting light which is generated from a microchip by laser irradiation, from a plurality of positions on the microchip; and

a procedure for specifying a position in which an integrated value or an average value of a detected intensity of the light in a region where a plurality of preset points exists becomes maximum.

(2) The optical position adjusting method according to (1), in which in the procedure for specifying the position, a relationship between a detected position of the light and the integrated value or the average value of the detected intensity of the light is assumed to follow a pre-stored probability distribution, a distribution parameter of the probability distribution is estimated on the basis of a pre-stored stochastic method, and thus the position in which the integrated value or the average value of the detected intensity of the light becomes maximum is specified by the estimation.

(3) The optical position adjusting method according to (2), in which in the procedure for specifying the position, the probability distribution is set to two-dimensional distribution.

(4) The optical position adjusting method according to (3), further including a procedure for assuming that a relationship of the integrated value or the average value of the detected intensity of the light from the position in which the integrated value or the average value of the detected intensity of the light is estimated to be maximum by the probability distribution to a predetermined position follows a one-dimensional distribution, and thus for specifying a position in which the integrated value or the average value of the detected intensity of the light becomes maximum by the one-dimensional distribution.

(5) The optical position adjusting method according to any one of (1) to (4), in which in the procedure for specifying the position, the position is set to a position in which a variation coefficient of the integrated value or the average value of the detected intensity of the light in a plurality of preset points becomes minimum.

(6) The optical position adjusting method according to (5), further including a procedure for specifying a position in which an area average of the integrated value of the detected intensity of the light in a plurality of preset areas becomes maximum.

(7) The optical position adjusting method according to (6), further including a procedure for specifying a first optimal position in which the integrated value of the detected intensity in the area of a maximum area average becomes maximum.

(8) The optical position adjusting method according to (7), in which the procedure for specifying the position in which the variation coefficient becomes minimum is a procedure for specifying a second optimal position in which the variation coefficient in the area of the maximum area average becomes minimum.

(9) The optical position adjusting method according to (8), further including a procedure for setting a relative position of the microchip with respect to the laser to the first optimal position or the second optimal position.

(10) The optical position adjusting method according to (9), in which the relative position is set to the second optimal position when the first optimal position and the second optimal position are different from each other.

(11) An optical position adjusting method of a microchip-type optical measuring apparatus, including:

a procedure for detecting light which is generated from a microchip by laser irradiation, from a plurality of positions on the microchip;

a procedure for specifying a position in which an area average of an integrated value of a detected intensity of the light becomes higher;

a procedure for specifying a first optimal position in which the integrated value or an average value of the detected intensity in an area where the area average becomes higher, becomes higher;

a procedure for specifying a second optimal position in which a variation coefficient of the integrated value or the average value of the detected intensity in the area where the area average becomes higher, becomes smaller; and

a procedure for setting a relative position of the microchip with respect to the laser to the first optimal position or the second optimal position.

REFERENCE SIGNS LIST

-   -   1 microchip-type optical measuring apparatus     -   2 microchip     -   21 orifice     -   22 sample flow passage     -   23 sample inlet     -   3 oscillating element     -   41 charging unit     -   42 electrode     -   51, 52 deflection plate     -   61 light source     -   62 detector     -   81, 82, 83 collection container     -   9 position adjustment unit     -   10 control unit     -   D detected position     -   F₁ fluorescence     -   L₁ laser 

The invention claimed is:
 1. An optical measuring apparatus, comprising: an irradiation detector configured to detect light generated by irradiating microparticles with a laser, the microparticles flowing through a channel, wherein the light is detected at a plurality of points, the plurality of points comprising a first plurality of points along a focus direction of the laser and a second plurality of points along a direction perpendicular to the focus direction of the laser; and at least one motor configured to change a relative position of the channel with respect to the irradiation detector based on a movement signal for a position selected based on an integrated value or an average value of a detected intensity of the light at the first plurality of points along a focus direction of the laser or at the second plurality of points along a direction perpendicular to the focus direction of the laser, wherein a stochastic method is used to estimate a distribution parameter of a probability distribution for modeling a relationship between a detected position of the light and the integrated value or the average value of the detected intensity of the light, and the movement signal for a selected position is based on using the stochastic method to estimate the distribution parameter.
 2. The optical measuring apparatus of claim 1, wherein the at least one motor is at least one stepping motor.
 3. The optical measuring apparatus of claim 2, wherein the at least one motor is configured to change a relative position of the channel with respect to the irradiation detector along at least a first axis and a second axis.
 4. The optical measuring apparatus of claim 1, wherein the at least one motor is further configured to change a relative position of the channel with respect to the irradiation detector along a third axis.
 5. The optical measuring apparatus of claim 1, wherein the probability distribution is selected according to an irradiation profile of the laser.
 6. The optical measuring apparatus of claim 1, wherein the movement signal is based on a variation coefficient of the integrated value or the average value of the detected intensity of the light.
 7. The optical measuring apparatus of claim 1, wherein the movement signal for an area is based on an area average of the integrated value of the detected intensity of the light.
 8. The optical measuring apparatus of claim 1, further comprising a processor configured to output the movement signal.
 9. An optical measuring method, comprising: detecting light by an irradiation detector, the light being generated by irradiating microparticles with a laser, the microparticles flowing through a channel, wherein the light is detected at a plurality of points, the plurality of points comprising a first plurality of points along a focus direction of the laser and a second plurality of points along a direction perpendicular to the focus direction of the laser; and performing a position adjustment using at least one motor, wherein the position adjustment changes a relative position of the channel with respect to the irradiation detector based on a movement signal for a position selected based on an integrated value or an average value of a detected intensity of the light at the first plurality of points along a focus direction of the laser or at the second plurality of points along a direction perpendicular to the focus direction of the laser, wherein a stochastic method is used to estimate a distribution parameter of a probability distribution for modeling a relationship between a detected position of the light and the integrated value or the average value of the detected intensity of the light, and the movement signal for a selected position is based on using the stochastic method to estimate the distribution parameter.
 10. The optical measuring method of claim 9, wherein the position adjustment changes a relative position of the channel with respect to the irradiation detector along at least a first axis.
 11. The optical measuring method of claim 10, wherein the position adjustment changes a relative position of the channel with respect to the irradiation detector along a second axis.
 12. The optical measuring method of claim 9, wherein the probability distribution is selected according to an irradiation profile of the laser.
 13. The optical measuring method of claim 9, wherein the movement signal is based on a variation coefficient of the integrated value or the average value of the detected intensity of the light.
 14. The optical measuring method of claim 9, wherein the movement signal for an area is based on an area average of the integrated value of the detected intensity of the light. 